Help Needed-2002 986 Overheating Issue

[Daviddelpauley]

Hey everyone.

 

My 2002 986 2.7l five speed base model has been having some overheating issues ever since I busted my passenger side radiator from hitting a pothole. I have replaced the radiator of course with an aftermarket one from RockAuto fitted for this vehicle, but am still having overheating issues.

 

You can occasionally here “gurgling” noises which makes me think it potentially needs bled after installing a fresh new radiator in it, but want some more opinions and ideas. 

 

On top of this, it appears I am also loosing fluid but cannot find any leaks. However, when the temperature gauge finally goes close to the 250° mark, you can pop the trunk and see it pressurized from droplets near the cap of the reservoir tank and it gets really warm back there. I have yet to lift up the trunk carpeting to see if the reservior is cracked causing me to lose fluids, but I don’t imagine this is the issue and it never gets abnormally low. I also cannot find a leak anywhere. When I say I’m loosing fluid, I mean it needs topped off nearly everytime. This is a process that has happened 5-6 times so I’m confident its not just the system needing more to cycle as if memory serves me right the base model only holds around 4 gallons of coolant total. 

 

Another additional thing worth mentioning, is that while replacing my radiator my mechanic slightly cracked the metal hosing belonging to my passenger side condenser. Of course all my freeon sprayed out, but was told it wouldn’t affect the main cooling system regarding the radiators themselves keeping the temp low. Any comment on that? 

 

Thank you all in advance for any help or advice you’re willing to offer, it is much appreciated. 

Edited October 3, 2018 by Daviddelpauley

[Loren]

Find a new mechanic - all Porsches need a vacuum fill to get all of the air out of the system. The tools are only about $100 so every shop should have them.

[wizard]

If the embossed part number on the top of your coolant reservoir cap does not end with the last 2 digits being -04, get a new cap that does - an original from Porsche ideally.

[Daviddelpauley]

I wasn’t aware of the vacuum fill requirement, I’ll be sure to get this done. I’m going to do this regardless, but do you think it will solve my problem with the symptoms I’ve listed? Thank you for telling me about the vacuum fill and for the radio code you provided me with yesterday lol

 

As for the lid, I will check tomorrow when I get home from work. I am nearly positive its the stock lid it came with, but I will confirm this tomorrow. Thank you for mentioning that though, might save me a big headache if it is indeed the wrong fuel cap. 

Edited October 4, 2018 by Daviddelpauley

[wizard]

Vacuum fill is the correct way. However, as the system is already filled, you might want to try 'burping' before doing anything else.

 

The burp valve is found beneath the black plastic cover around the coolant fill cap and oil fill cap. It has eight small bolts around its circumference and a metal clip across its top.

 

With the engine cold and the coolant at the correct fill level, lift the metal clip over the burp valve to the upright position and then start the car. Monitor both the temperature and coolant level until the engine reaches normal operating temperature. Return the metal clip to the horizontal position.

 

If you're doing this on an incline, the front of the car needs to face down the incline.

 

I'm sure that if you search for 'burping a Boxster cooling system', you'll find a video on how to do this. It's simple ... and can sometimes save a lot of work!

 

[Daviddelpauley]

Extremely informative! Thanks a bunch. I’ll give that a go when I make it home from work today and let you know my results. 

[wizard]

Forgot to mention to run your heater whilst running the engine with the burp valve open.

 

Whilst I've never done it, I believe that the valve can be left open (metal clip in upright position) whilst driving the car if necessary ... provided you keep a close eye on the coolant level.

[joe hurst]

yeah, sound ike you have some air in the system, they are a pig to bleed due to the engine and cooling system layout, lots of pipework compared to a frontmounted engine with the rad directly in front of it,.

 

doubt you have any other issues as the HG on these cars is pretty solid..

 

best of luck with it.

[Daviddelpauley]

I did the burping which did seem to make a big difference, as well as check the fuel cap and it was the correct one. 

 

Still yet though, in the end it started overheating. 

[wizard]

O.K.  By fuel cap you presumably mean coolant reservoir cap?

 

Just for the sake of clarity, is it correct that the cooling system was trouble-free until after the radiator was replaced?

 

When your engine gets up to 'hot', are the fans at the front coming on and, at low speed or high speed?

 

Do you have the facility to get the rear end of the car jacked up and safely supported whilst again trying with the burp valve?

 

Failing that, I guess it will require a drain and vacuum fill.

[TNT79Bronco]

Vacuum fill. Too much is at stake. It works like a champ and isn’t rocket science. Also, make sure other radiator is clean of debris. 

[Skullbiker]

On 10/4/2018 at 1:47 PM, wizard said:

Forgot to mention to run your heater whilst running the engine with the burp valve open.

 

Whilst I've never done it, I believe that the valve can be left open (metal clip in upright position) whilst driving the car if necessary ... provided you keep a close eye on the coolant level.

I also read about the metal “burp” clip being left up while running the car . - I know drivers of track cars have been known to do this .